Disk array system

ABSTRACT

In the disk array system, in the basic chassis, HDD modules are installed from a front surface in a front part of a backboard, and duplex CTL modules are installed up and down from a rear surface in a rear part, and duplex power source modules containing fans are installed in the left and right sides thereof. By the operation of the fans, in the rear part, the cooling air flows separately into each CTL module and into each power source module, and the cooling air having passed through the area of the duct by a block in the CTL module is drawn by the fans in the power source module through a ventilation hole and is then exhausted outside. The cooling air flow path to the plurality of ICs is divided by the block. The rotation speed of the fans is controlled by using a temperature sensor.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority from Japanese Patent ApplicationNo. JP 2007-88552 filed on Mar. 29, 2007, the content of which is herebyincorporated by reference into this application.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a disk array system (also referred toas a storage system) having a function to control a storage device suchas a HDD (Hard Disk Drive). More particularly, it relates toconfigurations of a system chassis and various modules installed thereinand ventilation and cooling structures of the system chassis and themodules.

BACKGROUND OF THE INVENTION

In a recent disk array system, mounting density has been increased andperformance thereof has been improved. Accordingly, higher coolingperformance has also been demanded in order to cope with the temperaturerise due to the increase in heat generation of component parts andresulting performance deterioration.

For example, in the disk array system of a predetermined method,elements such as boards (circuit boards) corresponding to variousfunctions and power sources are installed in the system chassis by meansof the structure and method of a module (also referred to as a unit,package, and assembly) to take the maintainability into consideration.Further, by mounting fans, heat sinks and others in the system chassisand modules, considerations are given to the ventilation and coolingfunction. For example, the high-density mounting and high coolingperformance are realized by the configuration in which each module isinserted through the opening in front or at the back of the chassis andconnected to the front or rear surface of a backboard inside the chassisand by the configuration in which a cooling air flows to the rearsurface (back side) from the front surface of the chassis via thebackboard by the fan operation.

For example, Japanese Patent Application Laid-Open Publication No.2004-022057 (Patent Document 1) discloses an example of theconfiguration of the conventional disk array system.

SUMMARY OF THE INVENTION

With respect to the configurations of the chassis and the module in theconventional disk array system, it is necessary to realize aconfiguration more effective than the conventional one in considerationof high density mounting and cooling performance. In particular, a diskarray system that can satisfy needs of an end user such as the sizereduction and higher cooling performance has been demanded.

The present invention has been made in view of the above describedproblems, and an object of the present invention is to provide atechnology that can realize an effective structure with respect to theconfigurations of the chassis, module, and the like and the ventilationand cooling structures in the disk array system in which high densitymounting and cooling performance are taken into consideration.

The typical ones of the inventions disclosed in this application will bebriefly described as follows. In order to achieve the above describedobject, the present invention provides a disk array system comprising agroup of storage devices (disk array) such as a HDD and a control devicethereof (controller or disk controller), wherein elements such ascontrollers and power sources are installed in the system chassis bymeans of the structure and method of a module, and in a redundantconfiguration in which each function is at least duplicated, each moduleis inserted through the opening in front or at the back of the chassisand connected to the front or rear surface of a backboard inside thechassis, and cooling is performed by the air ventilated to the rearsurface (back side) from the front surface of the chassis via thebackboard by the fan operation, and wherein technological means andconfigurations as shown below are provided.

In the disk array system of the present invention, in consideration ofthe high density mounting and cooling performance, new configurationsfor the chassis, modules and others and new cooling structure areprovided. The feature of this system lies in that the types of modulesand the layout thereof in the chassis are reviewed and the types ofmodules to be used are reduced, thereby reducing the size of the system.In the configuration of a basic chassis, a storage device module (forexample, the SAS HDD) and others are installed from the front surface inthe front part partitioned by the backboard, and duplex (two) controllermodules are installed up and down from the rear surface in the rearpart, and in the left and right areas thereof, duplex (two) power sourcemodules containing a fan unit (a plurality of fans) are installed. Inthe rear part, the two types of modules (four modules in total) aremainly installed. Further, in the configuration of an expanded chassis,an enclosure module is installed in place of the controller module. Thefan unit in the power source models comprises, for example, duplex fansinstalled front and back, and up and down.

A HDD connecter is disposed near the longitudinal center of thebackboard so as to correspond to the position of a connector of the SASHDD, and a connector of the controller is disposed near the upper andlower edges of the backboard so as not to interfere with that connector.Further, two power source modules are disposed in the left and rightareas of the two controller modules so as to correspond to positions ofthe left and right edges of the backboard.

Also, a cooling air flow path in the configuration of the chassis andmodules is devised. By the operation of the fan in the power sourcemodel, cooling air is taken from the front surface of the chassis tocool the storage device module and others, and then, it flows into therear part through the opening holes of the backboard. For example, inthe front part, the group of storage device modules disposed on theupper side is cooled by the cooling air much more than battery modulesand others disposed on the lower side. Also, when the cooling air flowsinto the rear part, the cooling is split, and one (first cooling air)flows into each controller module and the other (second cooling air)flows into each power source module through the opening holes of thebackboard. An almost equal amount of the cooling air is supplied to theduplex modules. In the rear part, inside of each power source module(power source unit) and controller module (components on a substratesuch as IC and others) are cooled by the cooling air.

In the power source module, the cooling air (second cooling air) passesthrough the power source unit on the side close to the connecter and isdrawn by the fan unit disposed close to the front surface side of thepower source module (rear surface side of chassis) at the back of thepower source. In the controller module, the cooling air (first coolingair) passes through the area of a duct structure formed by the disposedblocks and cools objects to be cooled such as IC and others on thesubstrate. The cooling air is not exhausted from the front surface side(rear surface side of chassis) of the controller module to the outside,but it is drawn by the fan units (fan) in the left and right powersource modules through a ventilation hole area at a position close tothe rear surface of the chassis in a first partition plate (and sidesurfaces of corresponding modules) between the controller module and thepower source module. Then, the cooling air from the controller sidetogether with the cooling air (second cooling air) from the power sourceside are exhausted outside through the exhaust port of the fan andexhaust hole on rear surface side of the chassis. In this manner, thecooling structure of the area combined with the power source module andthe controller module is made more efficient.

Further, this system gives special consideration to the efficientcooling of components (cooling object components) disposed on thecooling air flow path on the substrate in the controller module, inparticular, components such as a plurality of ICs adjacently disposed ina row in a back-and-forth direction of the chassis and heat sinksdisposed thereon. As the means for this purpose, an effective coolingair flow path (duct structure) that passes through the area of thecooling object components on the substrate is formed by a blockstructure for the cooling object components. For example, the block isdesigned to have a roughly trapezoidal shape in section in theback-and-forth direction of the chassis so as to have a slope(inclination) by a side of the trapezoid in the vicinity of the inflowof the cooling air toward the area of the cooling object components. Bythis means, the flowing cooling air can be smoothly applied to thecooling object components.

Further, in particular, by means of the change in layout and shape ofthe block, for example, by providing holes and concavity and convexity,the cooling air flow path to the area of the cooling object componentsis branched so as to correspond to a plurality of cooling objectcomponents on the substrate. By this branching, the cooling air can bedirectly applied to not only the components at a former stage close tothe backboard and connector side but also the components at a latterstage of the plurality of cooling object components, and the coolingperformance can be improved.

Further, in the controller, enclosure, and others, based on thetemperature detected by a temperature sensor provided in the chassis,the rotation speed of the fans in the power source modules arecontrolled. For example, when the detected temperature reaches thepredetermined value or more, the rotation speed of the fans areincreased.

The effects obtained by typical aspects of the present invention will bebriefly described below. According to the present invention, it ispossible to realize an effective structure with respect to theconfigurations of the chassis, module, and the like and the ventilationand cooling structures in the disk array system in which high densitymounting and cooling performance are taken into consideration.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing a configuration of an information processingsystem by a disk array system according to an embodiment of the presentinvention;

FIG. 2 shows a system configuration by the connection of modules tobackboards in a basic chassis and an expanded chassis in the disk arraysystem of the present embodiment;

FIG. 3 is a diagram schematically showing a configuration of a powersource system in the disk array system of the present embodiment;

FIG. 4 is a perspective view showing a hardware configuration of thebasic chassis seen from a side of a front surface (A);

FIG. 5 is a perspective view showing a hardware configuration of thebasic chassis seen from a side of a rear surface (B);

FIG. 6 is a perspective view showing a hardware configuration of theexpanded chassis seen from as side of a front surface (C);

FIG. 7 is a perspective view showing a hardware configuration of theexpanded chassis seen from a side of a rear surface (D);

FIG. 8A is a diagram showing a configuration of the front surface (A) ofthe basic chassis;

FIG. 8B is a diagram showing a configuration of the rear surface (B) ofthe basic chassis;

FIG. 9A is a diagram showing a configuration of the front surface (C) ofthe expanded chassis;

FIG. 9B is a diagram showing a configuration of the rear surface (D) ofthe expanded chassis;

FIG. 10 is a diagram schematically showing a planar structure of thebasic chassis in the horizontal direction and a representative flow (atthe normal time) of the cooling air;

FIG. 11 is a diagram schematically showing a planar structure of thebasic chassis in vertical direction (side surface) and a representativeflow of the cooling air;

FIG. 12 is a diagram showing the configuration of the basic chassis seenfrom the front surface side of the backboard;

FIG. 13A is a diagram showing a configuration of the connection of a HDDmodule to the backboard of the basic chassis in the case of a SAS-HDD;

FIG. 13B is a diagram showing a configuration of the connection of a HDDmodule to the backboard of the basic chassis in the case of a SATA-HDD;

FIG. 14A is a diagram schematically showing a planar configuration of apower source module installed in the basic chassis and its periphery inthe horizontal direction;

FIG. 14B is a diagram schematically showing a planar configuration of apower source module installed in the basic chassis and its periphery inthe vertical direction (side surface);

FIG. 15 is a perspective view showing a disassembled state of thestructure of a CTL module installed in the basic chassis;

FIG. 16 is a diagram showing a CTL substrate stored in the CTL module,components to be installed thereon, and the peripheral configurationthereof;

FIG. 17 is a diagram showing the structure of a block to be installed inthe CTL module with a three-side view and an isometric view;

FIG. 18 is a diagram showing a cooling air flow path (duct structure) bymeans of the block and the like in the CTL module;

FIG. 19 is a diagram showing an example of the processing flow of a fancontrol in the disk array system of the present embodiment; and

FIG. 20 is a diagram schematically showing a representative flow of thecooling air at the time when only one power source module (and fan unit)is operated in a planar structure of the basic chassis in a horizontaldirection.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, embodiments of the present invention will be described indetail with reference to the accompanying drawings. Note that componentshaving the same function are denoted by the same reference symbolsthroughout the drawings for describing the embodiment, and therepetitive description thereof will be omitted.

<Characteristics of Embodiment>

A disk array system according to an embodiment of the present inventionwill be described with reference to FIG. 1 to FIG. 20. The maincharacteristics of the present embodiment are as follows (see FIG. 10and others). In a disk array system 5, for example, in a basic chassis100, HDD modules 30 and others are installed in a front part 1partitioned by a backboard 20 from a front surface (A), and duplex CTLmodules 10 are installed up and down in a rear part 2 from a rearsurface (B), and further, duplex power source modules 40 containing aplurality of fans 43 are installed in the left and right areas thereof.By the operation of the fans 43, the cooling air flows from the frontsurface (A) to cool the HDD modules 30 and others, and it flows into therear part 2 through opening holes 220 of the backboard 20. Then, in therear part 2, one cooling air flows into each CTL module 10, and theother cooling air flows into each power source module 40. In the CTLmodule 10, the cooling air passes through an area 114 with a ductstructure by a block 150 and cools cooling object components such asICs. The cooling air is not exhausted from the CTL module 10, but isdrawn by the fans 43 in the power source module 40 through a ventilationhole 96 and the like of a partition plate 95, and then exhausted to theoutside together with the cooling air in the power source module 40. Bybranching the cooling air flow path to a plurality of components such asICs on a CTL substrate 120 by changing the structure of the block 150,the cooling air is directly applied also to the components of the latterstage. Further, the rotation speed of the fans 43 is controlled by theCTL 110 and others based on the temperature detected by a temperaturesensor 115.

<System (1)>

FIG. 1 shows the functional block configuration of an informationprocessing system in this disk array system 5. A host system 7 is a highorder information processing system such as a PC, a server, and a mainframe used by a user. The host system 7 and the disk array system 5 areconnected by communication means such as a SAN (Storage Area Network) 6or a LAN (Local Area Network).

The disk array system 5 mainly comprises a basic chassis 100 and anexpanded chassis 200. The basic chassis 100 is provided with both acontrol function (CTL 110 and the like) and a storage function (HDD 31group). The expanded chassis 200 is optional and is mainly provided withthe storage function (HDD 31 group).

A controller (CTL #1 and #2) 110 comprises a CPU 11, a bridge 12, aprogram memory (P memory) 13, a host I/F (also referred to as ahost-interface control unit, a channel I/F control unit, and the like)14, a data controller (DCTL) 15, a disk I/F (disk interface controlunit) 16, a cash memory (CM) 17, a switch (SW) 18, and others.

The CPU 11 executes a program stored in the program memory 13 throughthe bridge 12, thereby performing a processing to control the entiresystem. The DCTL 15 mutually connects each of the units and controlsdata transmission. The cache memory CM 17 is a shared memory to cash(store) the data in the CTL 110. The host I/F 14 is a processing unit towhich the host system 7 and the like are connected. The disk I/F 16 is aprocessing unit to which the HDD 31 group is connected via the SW 18.

The SW 18 has a SAS expander (EXP) function and an environmentmanagement function. The EXP function is a function such as an accesscontrol for the group of HDDs 31 corresponding to the SAS interface. Theenvironment management function includes a function (conventionalenvironment management function) to monitor and detect a trouble, afailure and a state such as connection regarding resources such as apower source (PS), fans, and the HDD 31 and a temperature managementfunction (cooling management function) including a fan control which isone of the characteristics of the present invention to be describedlater.

The HDD 31 is a HDD with the SAS interface (or SATA interface). On thephysical memory area provided by the HDD 31 group, a logical volumewhich is a logical memory area is set. Further, a RAID group by theplurality of HDDs 31 is set, and a RAID control can be executed. The SASHDDs 31 are connected by “two-path two-port” to the SW18 and a SW19.

The enclosure (ENC #1 and #2) 170 comprises the SW19 and performs aconnection with the CTL 110 and a relay to the ENC 170 when another ENC170 is connected. The SW 19 has a function similar to that of the SW18in the CTL110 of the basic chassis 100, and it takes charge of thecontrol inside the expanded chassis 200. The SW18 of the basic chassis100 and the SW19 of the expanded chassis 200 are connected, and the diskI/F 16 can access the target HDDs 31 in the basic chassis 100 and theexpanded chassis 200.

As shown by a chain line in the center, the CTL 110, ENC 170, HDD 31group, and others are duplicated, and an access can be made from oneside (#1 and #2) to the other side (#2 and #1).

The data processing in the disk array system 5 is as follows. Inresponse to a data write request (command) from the host system 7, theCTL 110 temporarily stores the data received from the host I/F 14 in theCM 17 and writes the data in the predetermined logical volume on the HDD31 group by the disk I/F 16. Further, in response to the data readrequest (command) from the host system 7, the CTL 110 reads the datafrom the predetermined logical volume on the HDD 31 group by the diskI/F 16 and stores the data temporarily in the CM 17, and then transmitsit to the host system 7 through the host I/F 14. Since a plurality ofhost I/Fs 14 and a plurality of disk I/Fs 16 are provided in thisconfiguration, a plurality of data inputs and outputs can be processedin parallel.

<System (2)>

FIG. 2 shows a system configuration (duplicated parts are omitted) forconnecting the modules (shown by m) to the backboards (BB) 20 and 20B inthe basic chassis 100 and the expanded chassis 200 of the disk arraysystem 5. Through the wirings of the backboard 20 and 20B, each of thecomponents is mutually connected. In the basic chassis 100, the HDDs 31of the plurality of HDD modules 30, duplex battery modules 50, and apanel module 60 are connected to the front surface of the backboard 20through the connectors. Further, the duplex CTL modules 10 and theduplex power source (PS) modules 40 are connected to the rear surface ofthe backboard 20. In the expanded chassis 200, the HDDs 31 of theplurality of HDD modules 30 are connected to the front surface of thebackboard 20B through the connectors. Further, the duplex ENC modules 70and duplex power source modules 80 are connected to the rear surface ofthe backboard 20B.

The SW18 of the CTL 110 (the bridge 12 and others are omitted here) andthe SW19 of the ENC 170 have the SAS expander (EXP) 21 corresponding tothe EXP function and the environment management unit (K) 22corresponding to the environment management function. Between thechassis, the connection between the EXPs 21 is made by a communicationcable and the like. Incidentally, the configuration in which theenvironment management unit (K) 22 is located at positions other thanthe SW18 and SW19 is also possible.

The EXP 21, based on a control from the high order disk I/F 16, controlsdata input and output accesses and the path switching and others to theHDD 31 group of each chassis by the SAS interface.

The environment management unit (K) 22, based on a control from the highorder (CPU 11 and others), monitors and detects a state of the powersource unit (41 and the like), fan unit (42 and the like), the HDD 31and the like installed in the chassis and performs the control of thepower source system and the control of the fan operation mode (fancontrol and cooling system control) using the fan unit (42 and the like)through the backboard 20 and others.

The power source module 40 comprises a power source unit 41 and a fanunit 42. The power source unit 41, based on an AC input, converts ACinto DC by an AC/DC conversion unit 411 and outputs DC power to thebackboard 20 from a DC output unit 412. The DC power is supplied to eachcomponent through the circuit of the backboard 20. The AC/DC conversionunit 411 corresponds to an SWPS 913. The fan unit 42 comprises aplurality of fans 43. The DC power (driving voltage) is inputted to thefan unit 42 from the power source 41 and others and the fans 43 arerotated. The rotation speed of the fan 43 is controlled by the drivingvoltage.

The power source module 80 on the expanded chassis 200 side hasbasically the same configuration (layout, cooling structure and the likeare different) as the power source module 40 on the basic chassis 100side, and it comprises a power source unit 81, a fan unit 82 (aplurality of fans 83) and others.

<Power Source System>

The configuration of the power source system of the disk array system 5will be described with reference to FIG. 3. This is the configuration ofthe power source of two systems corresponding to the duplex structuressuch as the CTL 110, ENC 170, and HDD 31 group. The power source unit 41(#1 and #2) in each power source module 40 (or 80) has a redundantconfiguration comprising two switching power sources (SWPS) 913(corresponding to 411). This power source unit 41 generates DC outputs(DC #1 and #2) based on two AC inputs (AC #1 and #2), respectively, andoutputs them to each component of the corresponding CTL 110 and thelike.

In each CTL 110, each processor 911 (CPU 11 and the like) can refer notonly to the memory 912 (CM 17 and the like) on its own side (forexample, #1) but also to the processor 911 and the memory 912 in the CTL110 of the other side (for example, #2). The read/write of the data, thecontrol information and others can be mutually performed between theduplex CTLs 110 so that no problem occurs even when one of them is introuble.

The DC output is supplied also to components such as the ENC 170, HDDs31, and the like from the corresponding power source unit in the samemanner. When the DC supply is cut off, the DC output is supplied fromthe battery module 50.

The battery module 50 corresponds to UPS (uninterruptible power sourceunit), and it contains a plurality of batteries and supplies anemergency power source. When the power supply is stopped due to thepower outage and the like, the battery module 50 supplies necessarypower to prevent the data loss and the like at the power outage. Morespecifically, the battery module 50 supplies at least the power requireduntil the data of the memory 912 (CM17 and the like) is written in theHDD 31 by the processor 911 of the CTL 110 and a premeditated stop isautomatically executed and completed. As a result, the data loss at thetime of the power outage can be prevented.

<Chassis>

Next, the external configuration of the entire hardware of the chassisof the disk array system 5 will be described with reference to FIG. 4 toFIG. 9 and others. The basic chassis 100 and the expanded chassis 200have a predetermined size which is mountable on a rack (frame) with asize in conformity to the predetermined standard. The size of the basicchassis 100 is Width: X1, Depth: Y1, and Height: Z1. The size of theexpanded chassis 200 is Width: X1, Depth: Y1, and Height: Z2.Specifically, as the size of the height of the chassis, 3U(approximately 133.35 mm), 4U, and others in EIA STANDARD EIA-310-D aresuitable. A ratio of the height (Z1) of the basic chassis 100 and theheight (Z2) of the expanded chassis 200 is preferably 4U:3U. Forexample, the rack (not shown) has a box shape with openings in its frontand rear surfaces, and each chassis (100 and 200) can be mounted up anddown therein.

The modules to be installed in each of the chassis include various typesmodules in the present embodiment, for example, the CTL module 10, theHDD module 30, the power source module 40, the battery module 50, thepanel module 60, the ENC module 70, and the power source module 80. Inthe installation of the HDD module 30 to the chassis, the hot plug isenabled. Operations such as insertion/removal and fixation of eachmodule to and from the chassis (100 and 200) by a person are performedby using an operating lever and the like provided in the module. Theoperation of the HDD module 30 is performed by using the operatinghandle and the like.

The operation in the case of the modules (CTL module 10, power sourcemodule 40, battery module 50, ENC module 70, and power source module 80in the present embodiment) provided with the operating lever is asfollows. First, when mounting the module in the chassis, a customerengineer or end user inserts the module into a predetermined area in thechassis, connects the connector thereof to the backboard 20, and thenmoves down the operating lever to fix the module (fixed state) by alatch action. When taking out the module from the chassis, the customerengineer or end user moves up the operating lever to release the fixedstate by a latch release action and removes the module from thepredetermined area in the chassis.

Each chassis is made of metal in general and has a box shape, and can bedisassembled by screws and others. A partition plate and the like whichcorrespond to the area to which each module is installed are provided inthe chassis. Further, an outer wall (main body) and the partition plateof the chassis are provided with the structure corresponding to theoperation of insertion/removal and fixation of the modules, for example,a guide rail (structure of grooves, protrusions, and the like) and areceiving portion of the operating lever (structure for receiving alatch portion and a hook portion of the operating lever). Further, thepartition plate (and its ventilation holes and the like) has a functionto adjust the flow of the cooling air in addition to the function offixation, reinforcement, and the like. Incidentally, the duplex twomodules have the same configuration and are configured to be attachableto both of the two mounting areas in the chassis.

<Basic Chassis>

A hardware configuration of the basic chassis 100 will be described withreference to FIG. 4 and FIG. 5. FIG. 4 is a diagram showing theconfiguration seen from the side of the opening of the front surface (A)of the basic chassis 100, and FIG. 5 is a diagram seen from the side ofthe opening of the rear surface (B) of the basic chassis 100.

In FIG. 4, the basic chassis 100 has openings in the front surface (A)and the rear surface (B) thereof, and the chassis is divided into afront part 1 (front surface side space) and a rear part 2 (rear surfaceside space) by the backboard 20 attached to the position at the midpointin the chassis as a boundary.

In the front surface (A) of the front part 1 of the basic chassis 100, aplurality of HDD modules 30 can be attached to the upper side thereof.Further, two battery modules 50 and the panel module 60 can be attachedto the lower side thereof. A bezel (door) 91 having an air permeabilitycan be attached to the front surface (A) in a state where each module isinstalled.

In FIG. 5, the rear surface (B) of the rear part 2 of the basic chassis100 has the configuration to which two CTL modules 10 and two powersource modules 40 can be mounted. Two power source modules 40 areinstalled on the left and right sides of the rear surface (B) of therear part 2, and two CTL modules 10 are installed in the area sandwichedbetween these modules.

<Expanded Chassis>

A hardware configuration of the expanded chassis 200 will be describedwith reference to FIG. 6 and FIG. 7. FIG. 6 shows a configuration of theexpanded chassis 200 seen from the side of the opening of the frontsurface (C), and FIG. 7 shows a configuration of the expanded chassis200 seen from the side of the opening of the rear surface (D).

In FIG. 6, the expanded chassis 200 has the openings in the frontsurface (C) and the rear surface (D) thereof, and the chassis is dividedinto a front part 3 (front surface side space) and a rear part 4 (rearsurface side space) by the backboard 20B attached to the position at themidpoint in the chassis as a boundary.

In the front surface (C) of the rear part 3 of the expanded chassis 200,the plurality (15 sets) of HDD modules 30 can be attached in a statealigned in a lateral direction. Incidentally, in the case of theexpanded chassis 200, other modules do not have to be installed on thefront surface (C) side.

In FIG. 7, the rear surface (D) of the rear part 4 of the expandedchassis 200 has the configuration to which two ENC modules 70 and twopower source modules 80 can be mounted. The duplex ENC modules 70 aredisposed side by side in an upper central area of the rear surface (D)of the rear part 4, and the duplex power source models 80 are disposedside by side in an area below them.

<Basic Chassis—Front and Rear Surfaces>

Next, FIG. 8A shows a configuration of the front surface (A) of thebasic chassis 100. In the front part 1, a plurality (up to 15 sets inthe present embodiment) of HDD modules 30 in an upright position areinstalled in a relatively wider upper area (A1) in a state aligned in alateral direction. Two battery modules (#1 and #2) 50 in a horizontalposition are installed side by side in a relatively narrower lower area(A2), and the panel module 60 is installed adjacent to the batterymodule, that is, in the lower right corner area of the front surface(A). The panel module 60 is a unit to display basic operations andstates such as ON and OFF of the power source in the system. Theboundary between the upper area (A1) and the lower area (A2) is providedwith a partition plate. The operating lever is provided at one positionof the lower side of the battery module 50.

FIG. 8B shows a configuration of the rear surface (B) of the basicchassis 100. In the rear part 2, the power source modules (#1 and #2) 40in an upright position are installed in the areas (B2) close to the leftand right sides of the rear surface (B). Two CTL modules (#1 and #2) 10in a horizontal position are installed up and down in the intermediatearea (B1) sandwiched between the power source modules. The same two CTLmodules 10 are installed upside down relative to each other. The sametwo power source modules 40 laterally reversed to each other areinstalled.

The partition plate 95 is provided at the boundary between the sidesurface of the power source module 40 and the side surface of the CTLmodule 10. A partition plate is provided at the boundary between theupper and lower two CTL modules 10.

A surface of a host I/F unit 103 corresponding to the host I/F 14 and anarea 107 of various types of terminals are provided in a part of thefront surface (106) of the CTL module 10. Two operating levers 104 areprovided at the left and right corners of the front surface of the CTLmodule 10, and the insertion/removal and the fixation of the CTL module10 by the two operating levers 104 can be performed.

An exhaust hole 48 and the like corresponding to the positions of theexhaust ports of a power source switch and a fan 43 are provided in thefront surface of the power source module 40. One operating lever 46 isprovided on one side surface of the power source module 40.

<Expanded chassis—Front and Rear Surfaces>

FIG. 9A shows a configuration of the front surface (C) of the expandedchassis 200. A plurality (up to 15 sets) of HDD modules 30 are installedinto the entire area of the front part 31 in a state aligned in alateral direction.

FIG. 9B shows a configuration of the rear surface (D) of the expandedchassis 200. In the rear part 4, two ENC modules 70 in a horizontalposition are installed side by side in an upper central area (D1) of therear surface (D). Two power source modules 80 in a horizontal positionare installed side by side in the lower area (D2). The two ENC modules70 and the two power source modules 80 are oriented in the samedirection.

The partition plate 97 is provided at the boundary between the upper ENCmodule 70 and the lower power source module 80. A partition plate isprovided between the left and right modules. One operating lever isprovided at the middle of the front surface of the ENC module 70.

The ventilation hole and the like corresponding to the positions of theexhaust ports of a power source switch and a fan (83) are provided inthe front surface of the power source module 80. Two operating leversare provided at the upper left and right sides of the power sourcemodule 80.

<Basic Chassis-Horizontal surface>

Next, FIG. 10 shows a schematic horizontal planar configuration(corresponding to the section of one CTL module 10 seen from above) ofthe basic chassis 100. Further, the arrow marks show representative flowand a flow amount of the cooling air (to be described later). The frontpart 1 has the HDD modules 30, and the rear part 2 has the CTL module(#1) 10 and the two left and right power source modules 40. Two fans 43as a fan unit 42 are provided in a row in a back-and-forth direction onthe rear side of the power source module 40. Ventilation holes 96 areprovided at the illustrated positions in each partition plate 95 betweenthe CTL module 10 and the power source module 40. An area 114 in which ablock 150 is disposed above such components as ICs on the substrate isprovided in the CTL module 10.

<Basic Chassis-Vertical Surface>

FIG. 11 shows a schematic vertical planar configuration (correspondingto the section of the CTL module 10 seen from the side thereof) of thebasic chassis 100. In the front part 1, the HDD module 30 is installedon the upper side, and the battery module 50 is installed on the lowerside. In the rear part 2, two CTL modules 10 are installed up and down.The block 150 is provided on the front side in the CTL module 10. Aventilation hole 105 is provided on the rear side of the side surface ofthe CTL module 10.

<Basic Chassis-Backboard Surface>

FIG. 12 shows the surface (front surface) of the backboard 20 in thebasic chassis 100. The backboard 20 is a circuit board with a roughlyflat planar shape and is fixed to a frame part positioned at the middleand slightly close to the front side of the basic chassis 100. Thebackboard 20 electrically connects each of the modules by connectorconnection and physically supports them. The fixation of the modulementioned here corresponds to the state in which the connector of therear surface of the module and the corresponding connector of thebackboard 20 are engaged and electrically connected.

A group of connectors (203, 205, and 206) for connecting the HDD module30, the battery module 50, the panel module 60, and the like areprovided on the front surface of the backboard 20. A group of connectors(201 and 204) for connecting the CTL module 10, the power source module40, and the like are provided on the rear surface of the backboard 20.Further, wiring patterns for the mutual connection between theconnectors and openings (ventilation holes) 220 through which thecooling air is supplied from the front part 1 to the rear part 2 areprovided in the backboard 20.

A plurality of connectors (HDD connectors) 203 for the connection of theHDD modules 30 with a longitudinal rectangular shape are disposed on azone extending in a lateral direction near the center (center zone) ofthe backboard 20. Further, connectors (battery connectors) 205 for theconnection of the battery modules 50 with a horizontal rectangular shapeare disposed below the HDD connectors 203. Further, a connector (panelconnector) 206 for the connection of the panel module 60 is disposednear the lower right corner of the backboard 20.

Further, connectors (CTL connectors) 201 to be connected to the CTLmodules 10 are disposed near the center of the upper and lower sides onthe rear surface side of the backboard 20, while interposing the area ofthe HDD connector 203 therebetween. That is, on the upper side, the CTLconnector 201 for the connection of the module (10) of a first CTL (#1)with a lateral rectangular shape is disposed. On the lower side, the CTLconnector 201 for the connection of the module (10) of a second CTL (#2)is similarly disposed. Further, connectors (power source connectors) 204for the connection of each power source module 40 with a longitudinalrectangular shape are disposed near the center of the left and rightsides of the backboard 20.

Further, in the center zone of the backboard 20, a plurality of openingholes 220 with a longitudinal rectangular shape are formed between theHDD connectors 203. In addition, opening holes 220 with a lateralrectangular shape are formed on both sides of the upper CTL connector201. The position, shape, size, and the like of the opening holes 220are designed based on the flow amount distribution of the cooling airflow path in the chassis (to be described later).

<HDD Module>

Next, FIG. 13A and FIG. 13B show the HDD module 30 (also referred to ascanister module). The HDD 31 is stored in the HDD module 30, and aconnector 32 to be connected to the connector 203 on the backboard 20 isprovided on the rear surface of the HDD module 30. A handle 301 isprovided on the front surface of the HDD module 30, and the operation ofinsertion/removal and fixation of the HDD module 30 can be performed bythis handle. The HDD module 30 has a uniform external appearance by thedesign of the handle 301 and the like. The HDD 31 of the HDD module 30installable in the present embodiment is either the Serial Attached SCSIHDD (SAS-HDD) 31 shown in FIG. 13A or the Serial ATA (SATA) interfaceHDD (SATA-HDD) 35 shown in FIG. 13B.

In FIG. 13A, in consideration of the position of the connector 32 of theSAS-HDD 31 and the installing position of the HDD module 30, theconnector position of each of other modules, the module installingposition, and shape are designed. Between the duplex CTL 110 (disk I/F16) and the SAS-HDD 31, the data input/output processing is performed bythe “two-port and two-path (2P)” according to the SAS interface. TheSAS-HDD 31 side has two ports (2P).

In FIG. 13B, when the HDD module 30 of the SATA-HDD 35 is installed, apath control board (I/F conversion substrate) 37 is interposed andconnected between the connector 36 of the SATA-HDD 35 and the connector(203) of the backboard 20 so as to match with the position of theconnector 32 of the SAS-HDD 31. More specifically, the connector 32 ofthe SAS-HDD 31 and the corresponding connector of the path control board37 are connected, and the connector 38 of the path control board 37 andthe corresponding connector (203) of the backboard 20 are connected. TheSATA-HDD 35 has one port (1P). In the case of the connection of theSATA-HDD 35, the I/F conversion is performed by the SATA and the SAS bythe control board 37 having the two ports.

<Power Source Module>

In FIG. 14A and FIG. 14B, the power source module 40 has an integratedmodule configuration including the power source unit 41 and the fan unit42, thereby reducing the size of the chassis. FIG. 14A shows a state inwhich one power source module 40 is installed between the outer wall 99of the basic chassis 100 and the partition plate 95 in a horizontalplane. FIG. 14B schematically shows the state in a vertical plane (sidesurface).

The power source unit 41 comprises a substrate 44, and a connector 45 tobe connected with the corresponding connector 204 of the backboard 20 isprovided on the rear surface side of the power source module 40. Aventilation hole 49 corresponding to the position of the ventilationhole 96 of the partition plate 95 and the position of the fan 43 isformed in a part close to the rear surface (B) in the side surfacefacing the CTL module 10 of the power source module 40. In the presentembodiment, the shape of the ventilation hole 49 is a convex shape whichcovers the area from the front fan 43 to the intermediate area betweenthese fans. The shape of the corresponding ventilation hole 96 of thepartition plate 95 is the same as that of the ventilation hole 49 or ashape covering the same.

The fan unit 42 has a redundant configuration to cool the inside of thebasic chassis 100 by the operation of a plurality of fans (air blowers)43. In the present embodiment, the fan unit 42 is similarly providedwith two fans 43 each in the upper and lower areas corresponding to theupper and lower two CTL modules 10, and further, it is provided with two(duplex) fans 43 aligned in a back-and-forth direction (in tandem). Inthis configuration, total of four fans 43 are provided in one powersource module 40. As the fan 43, for example, a fan such as anaxial-flow fan is used.

By a blade rotational motion by a DC power supply, each fan 43 takes airfrom an air-intake port facing the front surface (A) and exhausts theair from the exhaust port facing the rear surface (B). By the operationof the fan 43, the cooling air which flows in from the rear surface sideof the power source module 40 and is warmed through the power sourceunit 41 and the cooling air which is warmed through the CTL module 10and flows into the vicinity of an air intake port through eachventilation hole (105, 96, and 49) are taken in from the air intakeport, and then exhausted to the outside of the basic chassis 100 fromthe exhaust port in the back and the exhaust hole 48 of the power sourcemodule 40.

In the fan unit 42, since the duplex (plural) fans 43 are provided, evenwhen one fan stops rotating, the cooling effect can be secured by theoperation of the other fan. Further, even when the fan unit 42 in one ofthe left and right power source modules 40 stops rotating or even whenthe fan unit 42 is not installed in one of them, the cooling performancecan be secured by the operation of the fan unit 42 in the other powersource module 40. In that case, the cooling air in the CTL module 10flows into the fan unit 42 of the power source module 40 operatingnormally.

<Example of Conventional Technology>

Next, for comparison purpose, a configuration (chassis, module andcooling structure) in the disk array system of the conventionaltechnology (background technology) of the present embodiment will bebriefly described below. In this conventional technology, in the basicchassis, modules such as the HDD group, the battery, and the like areinstalled in the front part, that is, on the front surface side from thebackboard. Also, three types of modules such the CTL, power source, andfans and duplicated modules thereof, that is, a total of six modules areinstalled in the rear part, that is, on the rear surface side from thebackboard. In the rear part, two CTL modules are adjacently disposed upand down in the upper area, and two power source modules are adjacentlydisposed side by side in the lower area. Two fan modules are disposed onboth left and right sides of these modules. That is, in thisconfiguration, power source module and fan module are separated. The HDDis, for example, a HDD of a fiber channel I/F. Further, in the expandedchassis, the modules of the HDD group are installed in the front part,that is, on the front surface side from the backboard. Two types ofmodules of the ENC and the power source and duplicated modules thereof,that is, a total of four modules are installed in the rear part, thatis, on the rear surface side from the backboard. In the rear part, twoENC modules are adjacently disposed side by side in the upper area, andtwo power source modules are adjacently disposed side by side in thelower area.

<Design of Basic Chassis and Module>

The outline of the design for the basic structure of the basic chassis100 and the layout of each module in the chassis in the presentembodiment will be shown in the following (1) to (5). Basically, basedon the mounting details of the modules, required specifications, and thelike, the shape, size, layout, and the like of the module are designed,with taking into consideration the prevention of the interferencebetween the connectors in the backboard 20 and the cooling structure inthe chassis and the size reduction thereof (size standard and the like).With respect to the connector interference, the design is made so thatthe positions of the connectors to connect each module do not overlapone upon another and they are not located too close in the front andrear surfaces of the backboard 20.

(1) The layout of the HDD modules 30 is determined. Since thespecification basically requires the mounting of the SAS-HDD 31, theposition of the connector 32 on the side of the HDD 31 of the HDD module30 and the position of the corresponding connector 203 on the side ofthe backboard 20 are determined. Specifically, the positions of theconnectors (32 and 203) are located in the center zone of the backboard20 as shown in FIG. 12 and FIG. 13. Further, in the front part 1, thebattery module 50 and the like are disposed below the HDD module 30, andthe configuration of the front part 1 is thus roughly determined. Alsowhen the SATA-HDD 35 is installed, because of the interposition of thepath control board 37, the chassis has approximately the sameconfiguration as the case of SAS-HDD 31 in its entirety. By the changein the specification from the conventional configuration, the positionof the connector 32 of the SAS-HDD 31 for the backboard 20 of thepresent configuration differs from the conventional position of theconnector of the HDD of the fiber channel I/F for the backboard (movedfrom upper area to the center zone).

(2) The layout of the CTL module 10 is determined. The position of aconnector 111 of the CTL module 10 and the position of the correspondingconnector 201 on the backboard 20 are determined so as to prevent theconnector interference in the backboard 20, in particular, to preventthe overlap with the position of the connector 32 of the HDD module 30of the item (1). Specifically, the positions of the connectors (111 and201) are located at the positions near the upper and lower sides of thebackboard 20 as shown in FIG. 12 and FIG. 13. In the conventionalconfiguration, the two power source modules are disposed below the twoCTL modules (#1 and #2), and the connector of one CTL module (#2) isdisposed near the center of the backboard. In the present configuration,in the rear part 2, the conventional two power source modules are movedto the left and right side areas (power source module 40), and two CTLmodules (10) only are adjacently disposed up and down in the areabetween the power source modules. By this means, the position of theconnector of one (lower side) CTL module (#2) is moved further downwardthan the conventional position.

(3) The layout of the power source module 40 is determined. According tothe item (2), though the power source modules 40 are disposed in theleft and right side areas (B2) of the chassis, since the fan modulesexist in these areas in the conventional configuration, the power sourcemodules 40 are integrated with the fan modules. More specifically, thispower source module 40 is a combination type containing the power sourceunit 41 and the fan unit 42. Further, the positions of the connector 45of the rear surface of the power source module 40 and the correspondingconnector 204 on the backboard 20 are determined so as to prevent theconnector interference. Specifically, the positions of the connectors(45 and 204) with a longitudinal rectangular shape are located near theleft and right sides of the backboard 20 as shown in FIG. 12. Theconnectors of the power source module of the conventional configurationare disposed near the lower side of the backboard. In the presentconfiguration, however, these connectors are unified with connectors ofthe left and right fan modules and are moved to the positions near theleft and right sides of the backboard 20. In this manner, theconfiguration of the rear part 2 is roughly determined.

(4) Next, the structure of the flow path (and the flow amount and thelike) of the cooling air from the front surface (A) of the front part 1to the rear surface (B) of the rear part 2 of the basic chassis 100through the backboard 20 is considered and designed. The layout and sizedistribution of the module mounting area in the chassis, the layout ofthe partition plate and ventilation hole, the layout, area, and the likeof the opening hole 220 of the backboard 20 are considered and designed.Further, the design of the flow path is considered so as to equalize theflow amount to each duplex component (CTL modules 10 and the like).

(5) Further, in particular, the details of the cooling structure of acombination of the CTL module 10 and the power source module 40 in therear part 2 are determined. Specifically, the cooling air flow path isdetermined by the layout of the fan unit 42, the ventilation hole 96 ofthe partition plate 95, and no provision of the ventilation hole in thefront surface (106) of the CTL module 10. Further, as the coolingstructure in the CTL module 10, the position of the cooling objectcomponents (IC and the like) and the shape and position of thecorresponding block 150 are devised.

<Cooling Structure>

In FIG. 10 and FIG. 11, the basic cooling structure in the basic chassis100 is as follows. By the operation of the fan 43 of the fan unit 42,the outside air is taken in the front part 1 from the front surface (A),passes between the HDDs 31 and like as a cooling air, and then flowsinto the rear part 2 through the opening hole 220 of the backboard 20.In the rear part 2, the cooling air is divided and flows into the CTLmodule 10 and the power source module 40, respectively. By the partitionplate 95 between the power source module 40 and the CTL module 10, thecooling air is separated and rectified. Further, by the partition platebetween the two CTL modules 10, the cooling air is separated into theupper and lower areas.

In the rear part 2, the cooling air passes and cools each component inthe CTL module 10 and the power source unit 41 in the power sourcemodule 40, respectively. Such cooling air is drawn by the fans 43 in thepower source module 40 and is exhausted outside from the exhaust hole 48of the power source module 40 on the side of the rear surface (B). Inthe CTL module 10, the cooling object components are efficiently cooledby the area 114 with the duct structure formed by the block 150. Fromthe inside of the CTL module 10 to the inside of the power source module40, the cooling air flows into the fan 43 through the ventilation hole96 (and the corresponding ventilation holes 105 and 49) and the like ofthe partition plate 95. The position of the ventilation hole 96 in thepartition plate 95 between the CTL module 10 and the power source module40 is not in the entire surface of the partition plate 95 but at a partclose to the fan unit 42 on the rear side of the chassis. By this means,the cooling air is rectified and the cooling efficiency can be enhanced.The front surface 106 of the CTL module 10 is closed.

The cooling air flow path in the configuration in the basic chassis 100and the flow amount and flow distribution therein will be described withreference to FIG. 10 and FIG. 11. In FIG. 10, the distribution of theflow amount in this plane, for example, is as follows. It is assumedthat a flow amount 10 flows into the front part 1 (the HDD module 30group) from the front surface (A). In the rear part 2, the modulelayout, the area of the opening hole 220 and the like are designed sothat the cooling air is equally distributed to the CTL module 10 and thepower source module 40. More specifically, when considering one area ofthe upper and lower sides in the chassis, a flow amount of 5 of the flowamount of 10 from the front part 1 flows into one CTL module 10, and aremaining flow amount of 5 flows into the left and right power sourcemodules 40 in total (individually flow amount of 2.5). In the CTL module10, a flow amount of 2.5 of the flow amount of 5 is separately suppliedto each of the left and right power source modules 40 and drawn into thefan unit 42 (fans 43). In the fan unit 42 of each of the left and rightpower source modules 40, the flow amount of 2.5 from the power sourceunit 41 and the flow amount of 2.5 from the CTL module 10 are drawn, anda total of the flow amount of 5 is exhausted outside.

Further, the cooling air flown into one CTL module 10 of the rear part 2from the opening hole 220 of the backboard 20 cools each component(shown by rectangle) such as an IC and a heat sink (112) formed thereonprovided on a CTL substrate (120). The cooling air flows toward the rearsurface (B), and after cooling each component, it passes through theventilation holes 96 (and the corresponding ventilation holes 105 and49) of the left and right partition plates 95 and is drawn by the fans43 in each power source module 40 from inside of the CTL module 10.

Further, in FIG. 11, for example, the distribution of the flow amount inthis plane is as follows. It is assumed that the flow amount of 10 flowsinto the front part 1 from the front surface (A). The module layout, thearea of the opening hole 220 and the like are designed so that the flowamount is distributed at the rate of 8:2 in the HDD module 30 and thebattery module 50. In this design of the configuration, the HDD module30 is more efficiently cooled than the battery module 50. The flowamount is equally (5:5) distributed to the two (duplex) CTL modules 10of the rear part 2. From the HDD module 30 of the front part 1, a flowamount of 5 of the flow amount of 8 flows into the upper CTL module 10(CTL #1) and a remaining flow amount of 3 flows into the lower CTLmodule 10 (CTL #2). From the battery module 50 of the front part 1, aflow amount of 2 flows into the lower CTL module 10 (CTL #2). The flowamount of 5 in each of the upper and lower CTL modules 10 is drawn bythe fan unit 42 in the power source module 40 and is exhausted outside(broken line arrow mark).

<CTL Module>

Next, the cooling structure of the CTL module 10 will be described indetail with reference to FIG. 15 to FIG. 18 and the like.

FIG. 15 shows a structure of the CTL module 10 in a disassembled state.After storing and connecting component parts such as a CTL substrate(control package) 120, a host I/F unit 103, and a block 150 serving as afiller in a main body 101 of the CTL module 10, a top cover 102 servingas the upper surface is attached by screws and the like.

The CTL substrate 120 is attached to the bottom surface of the main body101. The main body 101 and the top cover 102 are mainly a package madefrom metal plate and they form the most part of the outer shape of theCTL module 10. The areas for the ventilation holes 105 corresponding tothe layout and shape of the ventilation holes 96 provided in thepartition plate 95 at the boundary with the power source modules 40 areprovided on both side surfaces of the main body 101. In the presentembodiment, the shape of the ventilation hole 105 is a horizontalrectangular by a plurality of slits. The front surface 106 (the rearsurface (B) side of the basic chassis 100) of the may body 101 has anotched area corresponding to the attachment of the host I/F unit 103.The host I/F unit 103 includes a substrate, a front panel, terminals andothers. The connector 111 and the like of the CTL substrate 120 areexposed on the rear surface side of the main body 101.

Further, various terminals, display elements, and the like are mountedin a part of the area of the front surface 106 of the CTL module 10,particularly in an area 107 near the center of the lower side thereof.In this area 107, for example, a display LED, LAN terminal, backendsystem terminal, remote adaptor terminal, UPS terminal and the like aremounted.

Further, on the left and right sides of this area 107, that is, at thebottom left and right corners of the front surface 106, the operatinglevers 104 are provided. The operating lever 104 is, for example, amechanism of fixing and releasing the CTL module 10 to and from thechassis by the operation of rotating a lever main body on a fixing axis(support point) at the corner of the CTL module 10, that is, theoperation of putting up and down the lever main body on the frontsurface 106 of the CTL module 10. When fixing the module, the lever mainbody is put down so as to be in parallel with the front surface 106. Bythis means, its one end (side surface side) is hooked on the structure(receiving portion) on the side of the partition plate 95 of thechassis, and the other side (inner side) is latched on the structure(receiving portion) on the side of the front surface 106 of the CTLmodule 10.

The block 150 is, for example, a structure made of a foamed material.The block 150 having a layout and shape corresponding to the coolingobjects (including the heat sink 112) on the CTL substrate 120 isattached onto the lower surface (area 114) of the top cover 102. Theblock 150 forms a part of the cooling air flow path (in other words, theduct) in the CTL module 10. Incidentally, in the heat sink 112illustrated here, the details of fins and the like are omitted.

<CTL Substrate>

FIG. 16 shows a component layout in the CTL substrate 120, the main body101 of its periphery, and the ventilation hole 105. The CTL substrate120 has a roughly flat-plate shape by a substrate 113. A connector (BBconnection connector) 111 for the connection to the backboard 20 isprovided on one side of the CTL substrate 120. On the substrate 113 ofthe CTL substrate 120, for example, main parts such as ICs are installedin accordance with the layout as illustrated. These parts generate arelatively large amount of heat by the operation thereof and are thecomponents in which particular consideration must be given to thecooling performance. These cooling objects include, for example, a CPU121, a SAS expander (EXP) 122, a bridge 123, a DCTL 124, a SAS interfacecontroller (SAS-CTL) 125 (consideration is given by including the heatsink 112 installed on the IC and the like). The CPU 121 corresponds tothe CPU 11. The bridge 123 corresponds to the bridge 12. The DCTL 124corresponds to the DCTL 15. The EXP 122 and SAS-CTL 125 correspond tothe SW 18. In the present embodiment, in about half the area on the sideclose to the connector 111 of the substrate 113, the block 150 isdisposed in the area 114 above the cooling object components includingthe CPU 121 to DCTL 124 (including the heat sink).

Further, in the present embodiment, a temperature sensor 115 is providedin front of the CPU 121 on the side close to the connector 111 on thesubstrate 113. Based on the temperature (temperature in the chassis)detected by the temperature sensor 115, a fan control described later isperformed. Also in the ENC module 70, similarly to the CTL module 10,the temperature sensor 115 is provided. In the CTL 110 and ENC 170, thefan control is performed by the environment management unit (K) 22.

The flow (arrow mark) of the cooling air to the cooling objectcomponents on the CTL substrate 120 will be described. That is, thecooling air which flows into the CTL module 10 first cools the peripheryof the cooling object (#1) 131 including the CPU 121 and the EXP 122provided in the vicinity of the connector 111 on the CTL substrate 120.Subsequently, the cooling air flows toward the rear surface (B) andcools the periphery of the cooling object (#2) 132 including the bridge123 and the DCTL 124 located at the latter stage of the cooling object131 at the former stage. Then, the cooling air flows further backwardand cools other components such as the SAS-CTL 125 near the rear surface(B). After each component in the CTL module 10 is cooled, since thefront surface 106 of the CTL module 10 is closed, the cooling air passesthrough the ventilation hole 105 of the main body 101 of the rear part(close to the rear surface (B)) and is drawn into the power sourcemodule 40 from the CTL module 10.

For the improvement in efficiency of ventilation/exhaust by the fan unit42, the exhaust hole and the like are not provided in the front surface106 of the CTL module 10 (closed as the flow path). Accordingly, the aironce exhausted outside from the fans 43 does not flow (circulate) intothe CTL module 10.

<Block>

In FIG. 17, the structure of the block 150 is shown by a three-side viewand an isometric view. The block 150 forms the cooling air flow path(duct structure) when disposed in the CTL module 10. The block 150 has ashape based on a main body with a roughly rectangular section providedwith concavity and convexity. In the block 150, concavity and convexityare formed to the main body thereof so that a space for the flow pathcorresponding to the layout and shape of the cooling object components(131 and 132) is formed. Further, in the block 150, the side of the mainbody thereof adjacent to the upper surface (top cover 102) of the CTLmodule 10 serves as a space for the ventilation, and a hole (conduit inthe block) 151 passing from that space to the cooling object component132 in the CTL module 10 is formed. Because of the block 150, thecooling air flow path (duct) can be configured to have a shape capableof efficiently cooling the cooling object components (131 and 132) andhaving rectifying effect.

FIG. 18 schematically shows a cooling air flow path in the periphery ofthe block 150 in the CTL module 10 by a section in the direction of theside surface of the chassis. In the block 150, slopes (inclination) by atrapezoid are formed in the portions corresponding to the side where thecooling air flows in and the side where the cooling air flow out.Because of the slopes, the flow of the cooling air is smoothed, and thecooling air can be efficiently applied to the cooling object component131. The slope is not limited to that having a flat surface, and the onehaving a curved surface is also available. The one air (intake air)taken in from the rear surface side of the CTL module 10 shown by a isguided by the slope of the block 150 and is applied to the coolingobject component 131 (for example, EXP 122) on the former stage, and theother air passes through the flow path by the hole 151 and the like ofthe block 150 and is directly applied to the cooling object component132 (for example, DCTL 124) on the latter stage. The cooling air whichflows out from the slope on the rear side of the block 150 is supplied(exhausted) backward (front surface 106 side) in the CTL module 10 asshown by b and is drawn by the fan unit 42 of the power source module40.

Incidentally, the inflow of the cooling air into the inner space and thehole 151 of the block 150 is, for example, from the lower surface of thetop cover 102. Further, for example, the structure in which the airflows from a notched part formed in the slope of the block 150 into theinner space of the block 150 and then reaches the hole 151 is alsopossible. The block 150 can have any shape as long as the cooling aircan be directly applied to the cooling object component 132 of thelatter stage, and various types can be used.

Since the cooling air flowing into the CTL module 10 is immediatelyapplied to the cooling object components (#1) 131, for example, the EXP122 and the CPU 121 close to the connector 111 side, the coolingperformance of the components is relatively high. Meanwhile, since theair once warmed through the EXP 122 and the like is applied to thecooling object components (#2) 132, for example, the bridge 123, theDCTL 124, and the like adjacent to the back thereof, the coolingperformance is relatively deteriorated. To cope with the situation, inthe present embodiment, by branching the cooling air flow path by meansof the structure of the block 150, the cooling air is directly appliedalso to the cooling object component 132 of the latter stage. In thismanner, the cooling performance of the cooling object component can beenhanced.

<Fan Control>

Next, a fan control in the disk array system 5 will be described. Theoperation of the fan unit 42 in the power source module 40 is controlled(fan control) mainly by the environment management unit (K) 22, forexample, the CTL 110 and the ENC 170, thereby adequately controlling thetemperature state of the system. The processing for the fan control isrealized by a program processing by a processor corresponding to theenvironment management unit (K) 22 or a hardware logical circuit. In thefan control, the environment management unit (K) 22 detects thetemperature (temperature in chassis) by the temperature sensor 115 andperforms a control (temperature control) to automatically switch theoperation mode of the fan unit 42 (fans 43) based on the detectedtemperature. As the operation mode, various types of modes different inrotation speed such as the fastest mode (abnormal time and the like),the high speed mode (intensive cooling time), the intermediate speedmode (normal time), and the low speed mode (waiting time) are provided.

In this temperature control, for example, when the sensor detectiontemperature is within the normal range, the control is set to theintermediate speed mode, and when it reaches the predeterminedtemperature or more, the mode is switched to the high speed mode. Bysetting the high driving voltage, the number of rotations (rotationspeed) of the fan is increased, and the flow amount of the cooling airis increased. In this manner, regardless of the presence of failures,the cooling performance can be secured. Incidentally, the coolingperformance is converted as [sensor detection temperature (temperaturein chassis)]=[outside temperature (environmental temperature)]+[0 to 7°C.]. For details, the change in the number of fan rotations by thedriving voltage is made by the switchover of a duty ratio of the inputpulse to the fan 43 (pulse frequency to the fan specification).

Further, as the conventional technology, the control in which the fanrotation speed is switched when the troubles and connections of the CTL,power sources (PS), fans and the like are detected in association withthe maintenance and replacement services has been known (troubledetection control and abnormal time control). In the disk array system5, the trouble detection control and the temperature control describedabove are combined together when performing the fan control.

In the trouble detection control, when the trouble of a part of the fanunit 42 or the fan 43, that is, a trouble, an operation stop, adisconnected state, and the like are monitored and detected, by theadjustment of the driving voltage for the fan unit 42, the operation ofthe fan unit 42 (fans 43) normally connected at that time is switched tothe operation mode so as to increase the rotation speed. For example,the operation mode is switched from the intermediate speed mode to thehigh speed mode. By this means, the flow amount of the cooling air isincreased, thereby compensating for the decrease of the coolingperformance due to the trouble. Even when one of the left and right fanunits 42 (a part of the fan 43) are out of service, the coolingperformance of the CTL 110 and the like can be secured. When restored tothe normal state, the operation mode is returned to the intermediatespeed mode or others.

The control conditions of this fan control are as follows. That is, theintermediate speed mode (or the low speed mode) is used when thetemperature in chassis is less than 39° C., and when it is 39 to 47° C.,the high speed mode is used, and when it is 47° C. or more, the fastestmode is used. Further, at the time of the system abnormal state, theoperation mode is set to the fastest speed mode. The number of rotationsof the fan at each operation mode is, for example, 3240 to 4112 rpm forthe low speed mode, 5400 to 6890 rpm for the intermediate speed mode,8100 to 10300 rpm for the high speed mode, and 10800 rpm or more for thefastest speed mode. Further, the system abnormal state includes, forexample, a state where one CTL is removed (disconnected state of the oneCTL module 10), a state where one PS is removed (disconnected state ofthe one power source module 40), a state where one PS is in an abnormalstate (abnormal state of the one power source module 40), a state wherethe number of fan rotations is insufficient (abnormal state of the fan43), and the like. Also, in the system abnormal state, an alarm(warning) is outputted together with the fan control. For example, whenthe state where the number of fan rotations is sufficient is detectedsuccessively a predetermined number of times (more than thepredetermined period), an alarm by means of an LED lighting, a message,and sound is outputted. Incidentally, even when the system is in anabnormal state, when one of the duplex modules normally operates, itfunctions as the disk array system.

In FIG. 19, the processing flow of the fan control in the basic chassis100 and the CTL 110 is as follows (S denotes the processing step). AtS1, when the CTL 110 is turned on (S1-Y), the temperature detected bythe temperature sensor 115 (temperature in chassis and the CTL intakeair temperature) is checked at S2. When the temperature is less than thepredetermined value, that is, when the temperature in chassis is lessthan 39° C. in the present embodiment (environment temperature is 32°C.) (S2-Y), in other words, when the environment temperature is in thenormal range, a fan connection state to the chassis is determined at S3.More specifically, it is determined whether the left and right two fanunits 42 (each four fans 43 for the left and right sides) of the chassisare normally connected to the CTL 110. Preferably, the state of aplurality of fans 43 is determined individually. When the left and righttwo fan units 42 are both connected, that is, when all the fans 43 arein a normal connected state (S3-Y), unless the system is in a waitingstate (no data input/output state) (S4-N), each fan unit 42 (each fan43) is driven in the intermediate speed mode by the predetermineddriving voltage at S7. Further, when the system is in a waiting state(S4-Y), the fan unit 42 (each fan 43) is driven in the low speed mode atS6. When the power of the CTL 110 is turned off (S10-Y), the operationof each fan unit 42 is stopped, and when it is not turned off (S10-N),the processing returns to S2.

Further, when the left and right fan units 42 are in a state of beingnot normally connected (S3-N) at S3, that is, when only one fan unit 42(or apart of the fans 43) is operating, the connected fan unit 42 (orthe fans 43) is driven in the high speed mode at S8.

Further, when the temperature (temperature in chassis) detected by thetemperature sensor 115 is the predetermined value (39° C.) or more at S2(S2-N), the mode is changed to the high speed mode or the like. In thiscase, since the environment temperature is higher than the normal range,this is considered as a highly heated state due to a high load of theCTL 110, a troubled state or a system abnormal state due to some causes.As for the troubled state, the failure of one fan unit 42 (or a part ofthe fans 43) and the disconnected state and the like are considered. Atthis time, the temperature state and the state of the fan unit 42 (fans43) and the like are determined at S5. More specifically, it isdetermined whether the temperature in chassis is equal to or higher thanthe predetermined value, in this embodiment, it is 47° C. or higher orwhether the system is in an abnormal state. When the temperature is lessthan the predetermined value (47° C.) or when the system is not in theabnormal state (S5-N), the fan unit 42 (fans 43) is driven in the highspeed mode at S8, and when the temperature is equal to or more than thepredetermined value (47° C.) or when the system is in an abnormal state(S5-Y), the fan unit 42 (fans 43) normally connected is driven in thefastest speed mode at S9.

<Cooling State Example>

FIG. 20 shows the flow of the cooling air at the time when only one ofthe left and right power source modules 40 (fan unit 42) of the basicchassis 100 is operated. For example, it corresponds to the state whereone PS is in an abnormal state or the state where one PC is removed, andthe state where the right power supply module (#2) relative to the rearsurface (B) is not connected or troubled is shown here. By the fancontrol described above, the operation of the fan unit 42 of the leftpower source module 40 (#1) normally connected and operated is switchedto the high speed mode or the fastest speed mode. By this means, thecooling air (each cooling air of the CTL modules (#1 and #2) 10 and eachcooling air of the power source units (#1 and #2) 41) in the rear part 2are all drawn and exhausted by the fan unit 42 of the normal one (#1).Accordingly, the cooling performance particularly in the CTL module 10is also secured.

In the fan unit 42, when one of the fans 43 aligned in a back-and-forthdirection is in trouble, the cooling performance is secured by theoperation of the other fan. Further, when one of the upper and lowerfans 43 is out of order, the cooling performance is secured by theoperation of the other fan.

<Effect of the Embodiment>

As described above, according to the present embodiment, the followingeffect can be obtained. In the present embodiment, the new structuresfor the chassis and modules as well as the cooling structure arerealized in consideration of the high density mounting and the coolingperformance. Particularly, in the basic chassis 100, the size reductionis realized by the reduction of the number of modules (CTL modules 10installed up and down and the power source modules 40 disposed left andright). Further, with respect to the cooling performance, because of theexhaust in the left and right power source modules 40 (fan unit 42), thestructure of the backboard 20 (connector position and opening hole 220),the ventilation hole 96 of the partition plate 95, the duct structure bymeans of the block 150 in the CTL module 10, and the fan control usingthe temperature sensor 115, the efficient cooling of each unit of theCTL board 120 can be realized in both the normal state and the abnormalstate. Since the cooling performance can be secured, the improvement ofthe processing performance and the reliability of the disk array systemcan be achieved.

Incidentally, although the structure of the basic chassis having the HDD31 has been described in FIG. 4 to FIG. 20, the present invention is notlimited to this. For example, it can be applied to the basic chassishaving no HDD 31. Further, although the structure of the basic chassis100 has been described in FIG. 4 to FIG. 20, the present invention canbe applied not only to the basic chassis 100 but also to the expandedchassis 200. In this case, in FIG. 4 to FIG. 20, the enclosure (ENC) ismounted in the position where the controller (CTL) is installed.

In the foregoing, the invention made by the inventors of the presentinvention has been concretely described based on the embodiments.However, it is needless to say that the present invention is not limitedto the foregoing embodiments and various modifications and alterationscan be made within the scope of the present invention.

The present invention can be used for equipment such as the disk arraysystem.

1. A disk array system provided with a group of storage devices and acontroller for controlling these devices, comprising: a basic chassishaving openings in front and rear surfaces thereof and a backboard fixedat a midpoint in its interior; and a plurality of storage devicemodules, two duplicated controller modules and two duplicated powersource modules as modules installed by insertion/removal and fixation toa front part and a rear part of the backboard, wherein the controllermodule contains a controller substrate and a flow path is closed at arear side surface of the chassis, and the power source module contains apower source unit and a fan unit disposed close to the rear side surfaceof the chassis at the back of the power source module and an exhausthole area is provided in a rear side surface of the chassis, theplurality of storage device modules are installed in the front part, thetwo power source modules are installed in areas close to left and rightside surfaces of the chassis in the rear part, and the two controllermodules are disposed up and down in areas between the two power sourcemodules, a ventilation structure for cooling air between the twocontroller modules and the two power source modules is provided atpositions near the fan units at the back of the power source modules,and by operation of the fan unit, cooling air taken from the chassisfront surface in the front part passes through the storage devicemodules and is then supplied to the rear part through an opening hole ofthe backboard, and in the rear part, one first cooling air flows intothe two controller modules and the other second cooling air flows intothe two power source modules, and the first cooling air passes throughan area of a plurality of cooling object components on the controllersubstrate in the controller modules and flows into a vicinity of the fanunits in the power source modules through the ventilation structure andis then drawn by the fan units, and the second cooling air passesthrough the power source units in the power source modules and is drawnby the fan units at the back thereof and is then exhausted outside froman area of the exhaust hole in the chassis rear side surface of thepower source modules by the fan units.
 2. The disk array systemaccording to claim 1, wherein the two power source modules laterallyreversed to each other are installed in areas close to left and rightside surfaces of the chassis and the two controller modules areinstalled upside down relative to each other in areas between the powersource modules, and on the front surface of the backboard, a pluralityof connecters for connecting the plurality of storage device modules areprovided near a center in a longitudinal direction, and connectors forconnecting the two controller modules are provided near upper and lowersides of the backboard with interposing the connectors for the storagedevice modules therebetween, and connector for connecting the two powersource modules are provided near left and right sides of the backboard.3. The disk array system according to claim 1, wherein the basic chassishas a first partition plate between the power source module and thecontroller module and a second partition plate between the twocontroller modules, and as the ventilation structure, an area of aventilation hole is provided in a part of the first partition plate andits corresponding side surfaces of the power source module and thecontroller module so as to correspond to the position of the fan unit atthe back of the power source module.
 4. The disk array system accordingto claim 1, wherein, as the storage device modules, a SAS-HDD modulehaving a SAS HDD and a connector at a lower side of a rear surfacethereof and a SATA-HDD module having a SATA interface HDD and aconnector at a lower side of a rear surface thereof can be installed,and when the SATA-HDD module is to be installed, a path control boardfor an interface conversion of SAS and SATA is interposed and connectedbetween the module and the backboard.
 5. The disk array system accordingto claim 1, wherein the plurality of storage device modules areinstalled in an upper area of the front part, and two duplicated batterymodules and a panel module having an operation panel are installed in alower area thereof, and a position and area of the opening hole of thebackboard are designed so that the cooling air of the front part flowsinto the upper area of the plurality of storage device modules more thanthe lower area of the battery modules and the cooling air flows almostequally into the areas of the upper and lower two controller modules ofthe rear part.
 6. The disk array system according to claim 1, whereinthe fan unit has duplex fans disposed front and back and up and down ineach of the two power source modules.
 7. The disk array system accordingto claim 1, wherein the controller has a CPU, a bridge, a datacontroller, a host interface unit, a disk interface unit, a SASexpander, and a cash memory, and the controller substrate includes theCPU, the bridge, the data controller, the SAS expander, and heat sinksinstalled thereon as the plurality of cooling object components.
 8. Thedisk array system according to claim 1, further comprising: an expandedchassis electrically connected to the basic chassis and having openingsin front and rear surfaces thereof and a backboard fixed at a midpointin its interior; and a plurality of storage device modules, twoduplicated enclosure modules and two duplicated power source modules asmodules installed by insertion/removal and fixation to a front part anda rear part of the backboard of the expanded chassis, wherein theenclosure module contains an enclosure substrate having a SAS expander,and the power source module of the expanded chassis contains a powersource unit and a fan unit having a plurality of fans, and the pluralityof storage device modules are installed in the front part of theexpanded chassis, and the two enclosure modules are installed side byside in an upper area and the two power source modules are installedside by side in a lower area in the rear part.
 9. A disk array systemprovided with a group of storage devices and a controller forcontrolling these devices, comprising: a basic chassis having openingsin front and rear surfaces thereof and a backboard fixed at a midpointin its interior; and a plurality of storage device modules, twoduplicated controller modules and two duplicated power source modules asmodules installed by insertion/removal and fixation to a front part anda rear part of the backboard, wherein the controller module contains acontroller substrate and a flow path is closed at a rear side surface ofthe chassis, and the power source module contains a power source unitand a fan unit disposed close to the rear side surface of the chassis atthe back of the power source module and an exhaust hole area is providedin a rear side surface of the chassis, the plurality of storage devicemodules are installed in the front part, the two power source modulesare installed in areas close to left and right side surfaces of thechassis in the rear part, and the two controller modules are disposed upand down in areas between the two power source modules, a ventilationstructure for cooling air between the two controller modules and the twopower source modules is provided at positions near the fan units at theback of the power source modules, by operation of the fan unit, coolingair taken from the chassis front surface in the front part passesthrough the storage device modules and is then supplied to the rear partthrough an opening hole of the backboard, and in the rear part, onefirst cooling air flows into the two controller modules and the othersecond cooling air flows into the two power source modules, and thefirst cooling air passes through an area of a plurality of coolingobject components on the controller substrate in the controller modulesand flows into a vicinity of the fan units in the power source modulesthrough the ventilation structure and is then drawn by the fan units,and the second cooling air passes through the power source units in thepower source modules and is drawn by the fan units at the back thereofand is then exhausted outside from an area of the exhaust hole in thechassis rear side surface of the power source modules by the fan units,and a plurality of cooling object components such as ICs on thecontroller substrate and heat sinks installed thereon are provided inthe controller module, and a block for forming a duct structure with apredetermined shape which is a part of the flow path of the cooling airis disposed above the plurality of cooling object components, and thefirst cooling air cools the plurality of cooling object componentsthrough the duct structure by means of the block.
 10. The disk arraysystem according to claim 9, wherein an area of some cooling objectcomponents adjacently disposed in a back-and-forth direction of thechassis is provided on a front side close to the backboard on thecontroller substrate in the controller module, and the block for formingthe duct structure is disposed above the area of some cooling objectcomponents, and the first cooling air flows into a backside of thechassis through the duct structure by the block and then flows into thepower source module through the ventilation structure.
 11. The diskarray system according to claim 9, wherein the block has a shape with aslope for smoothly introducing at least a part of the first cooling airso as to be directly applied to the cooling object component, in a crosssection taken in the back-and-forth direction of the chassis.
 12. Thedisk array system according to claim 9, wherein the block has a shape tobranch the flow path of the first cooling air in accordance withpositions of the cooling object components so that the cooling air isdirectly applied to the respective cooling object components.
 13. Thedisk array system according to claim 9, wherein the block has a shape ofa hole or a duct in its interior, which guides a part of the firstcooling air flowing from the backboard so as to be directly applied tothe cooling object components in a latter stage of several areas of somecooling object components.
 14. A disk array system provided with a groupof storage devices and a controller for controlling these devices,comprising: a basic chassis having openings in front and rear surfacesthereof and a backboard fixed at a midpoint in its interior; and aplurality of storage device modules, two duplicated controller modulesand two duplicated power source modules as modules installed byinsertion/removal and fixation to a front part and a rear part of thebackboard, wherein the controller module contains a controller substrateand a flow path is closed at a rear side surface of the chassis, and thepower source module contains a power source unit and a fan unit disposedclose to the rear side surface of the chassis at the back of the powersource module and an exhaust hole area is provided in a rear sidesurface of the chassis, the plurality of storage device modules areinstalled in the front part, the two power source modules are installedin areas close to left and right side surfaces of the chassis in therear part, and the two controller modules are disposed up and down inareas between the two power source modules, a ventilation structure forcooling air between the two controller modules and the two power sourcemodules is provided at positions near the fan units at the back of thepower source modules, by operation of the fan unit, cooling air takenfrom the chassis front surface in the front part passes through thestorage device modules and is then supplied to the rear part through anopening hole of the backboard, and in the rear part, one first coolingair flows into the two controller modules and the other second coolingair flows into the two power source modules, and the first cooling airpasses through an area of a plurality of cooling object components onthe controller substrate in the controller modules and flows into avicinity of the fan units in the power source modules through theventilation structure and is then drawn by the fan units, and the secondcooling air passes through the power source units in the power sourcemodules and is drawn by the fan units at the back thereof and is thenexhausted outside from an area of the exhaust hole in the chassis rearside surface of the power source modules by the fan units, thecontroller has an environment management unit, a temperature sensor isprovided in the controller module, and the environment management unitperforms a switching control so as to increase a rotation speed of thefan of the fan unit when a temperature detected by the temperaturesensor becomes equal to or higher than a predetermined temperature. 15.The disk array system according to claim 14, wherein the environmentmanagement unit monitors and detects a state of the power source moduleand the fan unit, and when it is judged as a disconnected state or anabnormal state, it performs a switching control so as to increase therotation speed of the fans of the fan unit in a normally connectedstate.
 16. The disk array system according to claim 14, furthercomprising: an expanded chassis electrically connected to the basicchassis and having openings in front and rear surfaces thereof and abackboard fixed at a midpoint in its interior; and a plurality ofstorage device modules, two duplicated enclosure modules and twoduplicated power source modules as modules installed byinsertion/removal and fixation to a front part and a rear part of thebackboard of the expanded chassis, wherein the enclosure module containsan enclosure substrate having a SAS expander, and the power sourcemodule of the expanded chassis contains a power source unit and a fanunit having a plurality of fans, the plurality of storage device modulesare installed in the front part of the expanded chassis, and the twoenclosure modules are installed side by side in an upper area and thetwo power source modules are installed side by side in a lower area inthe rear part, the enclosure has an environment management unit, atemperature sensor is provided in the enclosure module, and theenvironment management unit of the enclosure module performs a switchingcontrol so as to increase a rotation speed of the fan of the fan unit inthe power source module of the expanded chassis when a temperaturedetected by the temperature sensor becomes equal to or higher than apredetermined temperature.